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RE: [Teas] Yangdoctors last call review of draft-ietf-teas-yang-te-topo-08

2017-07-12 20:24:34
Hi Mahesh,

Thanks. We will fix these within next few days.

Regards,
- Xufeng

From: Mahesh Jethanandani [mailto:mjethanandani(_at_)gmail(_dot_)com]
Sent: Friday, July 7, 2017 2:14 PM
To: Xufeng Liu <xufeng(_dot_)liu(_dot_)ietf(_at_)gmail(_dot_)com>
Cc: Robert Wilton <rwilton(_at_)cisco(_dot_)com>; Benoit Claise 
<bclaise(_at_)cisco(_dot_)com>; Xufeng Liu <Xufeng_Liu(_at_)jabil(_dot_)com>; 
yang-doctors(_at_)ietf(_dot_)org; ietf(_at_)ietf(_dot_)org; 
teas(_at_)ietf(_dot_)org; 
draft-ietf-teas-yang-te-topo(_dot_)all(_at_)ietf(_dot_)org
Subject: Re: [Teas] Yangdoctors last call review of 
draft-ietf-teas-yang-te-topo-08

Also, couple of changes in the YANG modules:

Under revision, can you make sure there is a reference back to the RFC number 
that will be assigned to the draft. Something like:

  revision "YYYY-MM-DD" {
    description
     "Initial version";
    reference
     "RFC XXXX: YANG - TE Topology";
  }

with a note to RFC editor to replace XXXX with the number assigned to the RFC.

Prefix organization with IETF. Something like “IETF Traffic Engineering 
Architecture and Signaling (TEAS) Working Group”


Thanks.


On Jul 3, 2017, at 3:25 PM, Xufeng Liu 
<xufeng(_dot_)liu(_dot_)ietf(_at_)gmail(_dot_)com<mailto:xufeng(_dot_)liu(_dot_)ietf(_at_)gmail(_dot_)com>>
 wrote:

HI Rob,

Just posted https://datatracker.ietf.org/doc/draft-ietf-teas-yang-te-topo/  to 
fix the snippets, along with a missing IANA entry.

Thanks,
- Xufeng

From: Robert Wilton [mailto:rwilton(_at_)cisco(_dot_)com]
Sent: Monday, July 3, 2017 5:13 AM
To: Xufeng Liu 
<xufeng(_dot_)liu(_dot_)ietf(_at_)gmail(_dot_)com<mailto:xufeng(_dot_)liu(_dot_)ietf(_at_)gmail(_dot_)com>>;
 'Benoit Claise' 
<bclaise(_at_)cisco(_dot_)com<mailto:bclaise(_at_)cisco(_dot_)com>>; 'Xufeng 
Liu' <Xufeng_Liu(_at_)jabil(_dot_)com<mailto:Xufeng_Liu(_at_)jabil(_dot_)com>>; 
'Mahesh Jethanandani' 
<mjethanandani(_at_)gmail(_dot_)com<mailto:mjethanandani(_at_)gmail(_dot_)com>>;
 yang-doctors(_at_)ietf(_dot_)org<mailto:yang-doctors(_at_)ietf(_dot_)org>
Cc: ietf(_at_)ietf(_dot_)org<mailto:ietf(_at_)ietf(_dot_)org>; 
teas(_at_)ietf(_dot_)org<mailto:teas(_at_)ietf(_dot_)org>; 
draft-ietf-teas-yang-te-topo(_dot_)all(_at_)ietf(_dot_)org<mailto:draft-ietf-teas-yang-te-topo(_dot_)all(_at_)ietf(_dot_)org>
Subject: Re: [Teas] Yangdoctors last call review of 
draft-ietf-teas-yang-te-topo-08

Hi Xufeng,
Thanks for updating the modules to be NMDA compliant.  I think that getting 
structural consistency across the IETF YANG modules will make them far more 
compelling as a solution.
I noticed that some of the snippets of YANG tree output in the draft still 
illustrate using the "split oc-style config/state structure" and hence also 
need to be updated.  Probably this could be done as part of the WG LC.
To find the instances, just search the draft for "rw config" and "ro state".
Thanks,
Rob

On 02/07/2017 22:42, Xufeng Liu wrote:
An updated revision of the TE topology model has been posted at 
https://tools.ietf.org/html/draft-ietf-teas-yang-te-topo-10.

This new revision now contains the NMDA compliant module and a companion 
“-state” module, after the I2RS topology model that we augment has been update 
with a “-state” module.

Now that this issue has been solved, the authors and contributors think that 
the draft is ready for the last call.

Thanks,
- Xufeng

P.S. Because of the structure changes of the TE topology model, all augmenting 
models need to be updated. Sorry for the short notice.

From: Teas [mailto:teas-bounces(_at_)ietf(_dot_)org] On Behalf Of Benoit Claise
Sent: Monday, June 26, 2017 6:46 AM
To: Xufeng Liu 
<Xufeng_Liu(_at_)jabil(_dot_)com><mailto:Xufeng_Liu(_at_)jabil(_dot_)com>; 
Robert Wilton 
<rwilton(_at_)cisco(_dot_)com><mailto:rwilton(_at_)cisco(_dot_)com>; Mahesh 
Jethanandani 
<mjethanandani(_at_)gmail(_dot_)com><mailto:mjethanandani(_at_)gmail(_dot_)com>;
 yang-doctors(_at_)ietf(_dot_)org<mailto:yang-doctors(_at_)ietf(_dot_)org>
Cc: Benoit Claise 
<bclaise(_at_)cisco(_dot_)com><mailto:bclaise(_at_)cisco(_dot_)com>; 
ietf(_at_)ietf(_dot_)org<mailto:ietf(_at_)ietf(_dot_)org>; 
teas(_at_)ietf(_dot_)org<mailto:teas(_at_)ietf(_dot_)org>; 
draft-ietf-teas-yang-te-topo(_dot_)all(_at_)ietf(_dot_)org<mailto:draft-ietf-teas-yang-te-topo(_dot_)all(_at_)ietf(_dot_)org>
Subject: Re: [Teas] Yangdoctors last call review of 
draft-ietf-teas-yang-te-topo-08

Hi Xufeng,

Hi Benoit,



-----Original Message-----

From: Benoit Claise [mailto:bclaise(_at_)cisco(_dot_)com]

Sent: Thursday, June 22, 2017 6:12 AM

To: Robert Wilton 
<rwilton(_at_)cisco(_dot_)com><mailto:rwilton(_at_)cisco(_dot_)com>; Xufeng Liu 
<Xufeng_Liu(_at_)jabil(_dot_)com><mailto:Xufeng_Liu(_at_)jabil(_dot_)com>;

Mahesh Jethanandani 
<mjethanandani(_at_)gmail(_dot_)com><mailto:mjethanandani(_at_)gmail(_dot_)com>;
 yang-doctors(_at_)ietf(_dot_)org<mailto:yang-doctors(_at_)ietf(_dot_)org>

Cc: ietf(_at_)ietf(_dot_)org<mailto:ietf(_at_)ietf(_dot_)org>; 
teas(_at_)ietf(_dot_)org<mailto:teas(_at_)ietf(_dot_)org>; 
draft-ietf-teas-yang-te-topo(_dot_)all(_at_)ietf(_dot_)org<mailto:draft-ietf-teas-yang-te-topo(_dot_)all(_at_)ietf(_dot_)org>

Subject: Re: [Teas] Yangdoctors last call review of 
draft-ietf-teas-yang-te-topo-

08



Dear draft-ietf-teas-yang-te-topo authors,

Hi Xufeng,



OK, by tooling, I don't mean the pyang plugins that I have been

working on to convert between different types of models.  As you

aware, the TE YANG models can easily be converted to NMDA style since

I have already done it

(https://github.com/rgwilton/ietf-models-to-combined).



My comment actually relates to the fact the structure used by TE YANG

modules don't match any other YANG modules - they are using their own

unique style of structure.

This is an important issue to resolve.



Today, there are three common styles of modules:

(1) IETF style split config/state trees (e.g. ietf-interfaces).

(2) IETF NMDA style combined config/state trees (i.e. where all IETF

modules are heading to).

(3) OpenConfig style modules with the config/state containers

immediately above the config leaves.



Tooling is likely to be optimized to work with these model structures,

but the TE modules do not fit into any of the three styles above.

They are a yet another OpenConfig-like style, but that is different

enough that tooling that is designed to work with OpenConfig style

YANG modules would likely not work with the TE YANG modules.



Specifically, for clients that expecting to work with an OpenConfig

style YANG module, then if it knows the path to config leaf X, then

they would expect the applied config value to be available at the path

"../state/X".  But, this doesn't hold for the structure being used in

the TE YANG models.



I believe strongly that the models being produced by organizations

should be structures in a consistent way, hence why I think that the

published standard version of the TE YANG modules should immediately

align to the NMDA style.

Agreed.

Here is the OPS and RTG AD message:

https://www.ietf.org/mail-archive/web/netmod/current/msg18252.html



I understand that the I2RS topology YANG modules will be improved to the

NMDA style.

[Xufeng] The I2RS topology model is already NMDA style, but the NMDA models are 
not immediately implementable without NETCONF/RESTCONF protocol update. We will 
need the "-state" module for the I2RS topology model (and for all the top-level 
models) for now.
Adding -state to the Appendix is a possibility.
"In all cases, the NMDA and non-NMDA modules SHOULD be published in the same 
document, with NMDA modules in the document main body and the non-NMDA modules 
in an Appendix."
See https://www.ietf.org/mail-archive/web/netmod/current/msg18252.html




While the NMDA is nice, the NMDA discussions have already significantly delayed 
publishing new models, and doing NMDA without staging will further delay the 
process.
This is not solving the important issue brought up by Rob Witlon:
My comment actually relates to the fact the structure used by TE YANG modules 
don't match any other YANG modules - they are using their own unique style of 
structure.
Regards, B.






Thanks,  Xufeng



Regards, Benoit



Thanks,

Rob





On 22/06/2017 04:16, Xufeng Liu wrote:

Hi Rob,



While the tooling is very nice to have, especially for writing new

models or converting models, we do not have to use it for every

model. It seems not necessary to use the tooling on this model for

now. We already know that we can manually convert it to NMDA style if

needed.



Thanks,

- Xufeng



-----Original Message-----

From: Robert Wilton [mailto:rwilton(_at_)cisco(_dot_)com]

Sent: Wednesday, June 21, 2017 5:34 AM

To: Xufeng Liu 
<Xufeng_Liu(_at_)jabil(_dot_)com><mailto:Xufeng_Liu(_at_)jabil(_dot_)com>; 
Mahesh Jethanandani

<mjethanandani(_at_)gmail(_dot_)com><mailto:mjethanandani(_at_)gmail(_dot_)com>;
 yang-doctors(_at_)ietf(_dot_)org<mailto:yang-doctors(_at_)ietf(_dot_)org>

Cc: ietf(_at_)ietf(_dot_)org<mailto:ietf(_at_)ietf(_dot_)org>; 
teas(_at_)ietf(_dot_)org<mailto:teas(_at_)ietf(_dot_)org>;

draft-ietf-teas-yang-te-topo(_dot_)all(_at_)ietf(_dot_)org<mailto:draft-ietf-teas-yang-te-topo(_dot_)all(_at_)ietf(_dot_)org>

Subject: Re: [Teas] Yangdoctors last call review of

draft-ietf-teas-yang-te-topo-

08



Hi Xufeng,



On 12/06/2017 22:28, Xufeng Liu wrote:

Hi Mahesh,



Thank you much for the review. We have submitted an updated draft

(https://tools.ietf.org/html/draft-ietf-teas-yang-te-topo-09) to

address these issues. More detailed explanations are put below

inline.

If the responses and updates are satisfactory, we are ready for the

last call.



Best regards,

- Xufeng



-----Original Message-----

From: Mahesh Jethanandani [mailto:mjethanandani(_at_)gmail(_dot_)com]

Sent: Wednesday, May 24, 2017 11:44 AM

To: yang-doctors(_at_)ietf(_dot_)org<mailto:yang-doctors(_at_)ietf(_dot_)org>

Cc: ietf(_at_)ietf(_dot_)org<mailto:ietf(_at_)ietf(_dot_)org>; 
teas(_at_)ietf(_dot_)org<mailto:teas(_at_)ietf(_dot_)org>;

draft-ietf-teas-yang-te-topo(_dot_)all(_at_)ietf(_dot_)org<mailto:draft-ietf-teas-yang-te-topo(_dot_)all(_at_)ietf(_dot_)org>

Subject: Yangdoctors last call review of

draft-ietf-teas-yang-te-topo-08



Reviewer: Mahesh Jethanandani

Review result: Ready with Issues



Document reviewed: draft-ietf-teas-yang-te-topo-08



Status: Ready with Issues



I am not an expert in Traffic Engineering. This review is looking

at the draft from a YANG perspective. With that said, I have

marked it as “Ready

with Issues”

because of some of the points discussed below.



Summary:



This document defines a YANG data model for representing,

retrieving and manipulating TE Topologies. The model serves as a

base model that other technology specific TE Topology models can

augment.



Comments:



Almost all the containers in the model are presence containers. Is

there a reason why they have to be presence containers? Note, that

presence containers are containers whose existence itself

represents configuration data. What particular configuration data

is each container

representing in itself?

[Xufeng] Containers that use “presence” are:

    - Container “underlay”

      o  We have changed 13 occurrences of such containers to be

not

presence container.

    - Container “te” under augmentation

      o  To indicate that “TE” is enabled (configuration data)

      o  Also used to do augmentation. The “presence” statement can

prevent the mandatory child from affecting augmented base model.

    - /nw:networks/nw:network/nw:network-types/te-topology!

      o  A mechanism required by I2RS topology model to specify the

topology type.

It is difficult to co-relate the diagram with the model itself

because of different terms being used to define different parts of

the model.

There is “TE Topology Model” and then there is “Generic TE

Topology

Model”.

Are these one and the same models? If so, a common term for both

of them would be helpful.

[Xufeng] Yes. These two terms are the same. Figure 12, Figure 13,

and relevant

descriptions have been updated to make the document consistent.

There is extensive use of groupings in the document. However, not

all instances of groupings are used multiple number of times.

Where they are not being repeated, it would be better to move the

grouping directly where the uses statement resides. Case in point

the grouping

connectivity-label-restriction-list.

[Xufeng] We have removed the following groupings

      te-link-augment

      te-node-augment

      te-termination-point-augment

      te-topologies-augment

      te-topology-augment

      te-link-state-underlay-attributes

      te-node-state-derived-notification

      te-topology-type



The remaining groupings have been kept so that we can:

    - Share the groupings in this model

    - Prepare to be shared by a model augmenting this model

    - Prevent a grouping or configuration section from being too long

    - Improve readability



The split between config and state containers does not seem to

follow any particular pattern.

[Xufeng] The pattern is clear:

For each manageable entity (object), there is a config container

and state

container. The configurable properties go into the config container

and state properties go into the state container. Such objects are

identified by a list item or a presence container so that the

“create”, “delete”, and “modify”

operations

can be performed on them. The non-presence containers do not

represent configuration data so they do not introduce such objects.

It is neither a top level split, as is the case with existing IETF

models,

[Xufeng] We could not do top level split because the base I2RS

network

topology model

(https://tools.ietf.org/html/draft-ietf-i2rs-yang-network-topo-

12) that we augment does not have the top-level split (for its own

reasons).

nor do they follow the OpenConfig style of splitting config and

state under each relevant leaf,

[Xufeng] The pattern is consistent with this style in principle,

with some

adjustments to fit to our multiple levels of hierarchy.

This is effectively a new forth style of YANG models that is not

consistent with any of the three existing styles, i.e.:

   - Current IETF config/state split model style

   - NMDA combined config/state tree

   - OpenConfig split config/state containers immediately above the

config true leaves.



Tooling that it designed to work with OpenConfig models will need

customization to work with these TE models because the config/state

containers will not be where the tooling expects them to be.



Thanks,

Rob



.







Mahesh Jethanandani
mjethanandani(_at_)gmail(_dot_)com<mailto:mjethanandani(_at_)gmail(_dot_)com>